Centering-tool for circular objects.



I 1. E.MURRAY. CENTERING TOOL FOR ClRCULAR OBJECTS/ h I APPLICATIONFILED JUNE 9., 1916. 1,230,01 5.. Iatgnfpgd June 12, 1917.

JAMES E. MURRAY, OF KANSAS CITY, MISSOURI.

Specification of Letters Patent.

GENTERING-TOOL FOR CIRCULAR OBJECTS.

Patented June 12, 1917.

Application filed June 9, 1916. Serial No. 102,721.

To all whom it may concern:

Be it known that I, JAMES E. MURRAY, a

. citizen of the United States, residing at Kansas City, in the countyof Jackson and State of Missouri, have invented certain new and usefulImprovements in Centering- Tools for Circular Objects; and I do herebydeclare the following to be a full, clear, and exact description ofthe-invention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to new and useful improvements in centering toolsfor circular objects and the principal object of the invention is toprovide a device by which it is possible to readily find the center of ashaft or any other circular object in order that the same may beproperly centered for turning in a lathe.

Another object of the invention is to combine a centering device with apair of calipers so that the same may be used in conjunction.

A still further object of the invention is to provide a device which maybe readily attached to an ordinary pair of calipers without materiallychanging the same.

With these and other objects in view, the invention consists in thenovel combination and arrangement of parts which will be fully set forthin the following specification and accompanying drawing, in which Figure1 is a view showing this improved device as it would appear in use.

Fig. 2 is a fragmentary side View of Fig. 1.

Fig. 3 is a sectional view through the tool, and

Fig. 4 is an enlarged detail sectional view through the pivot of thecaliper arms showing the tool as it would appear in place.

Referring to the drawing the numeral 1 designates the pivot of thecaliper arms consisting of the cylindrical body 2 formed with heads 3 atopposite ends. An enlarged cylindrical portion 4 is formed at the upperend of the. body 2 adjacent the head 3 the use of which will appear asthe description proceeds. The caliper arms are designated by the numeral5 and provided with the usual points 6 while the ends opposite thepoints 6 are arranged to have their inner edges engage the portion 2 ofthe pivot l and a suitable spring 7 tends to move said caliper arms intoopen position. In order to hold the caliper arms in proper adjustedposition the usual screw8- is attached to one of the arms and hasthreaded thereon a nut 9 which engages the opposite arm and it will thusbe seen that upon adjusting the nut on the screw the points 6 may beseparated to various degrees of width.

The attachment consists of the arm 10 formed at one end with the slottedenlargement 11, the slot 12 of which is adapted to receive the enlargedportion 4 of the pivot l in order to hold the arm 10 in proper position.This arm 10 is formed at its forward end with the tool steel blade 13which as shownfin Fig. 3 is triangular in cross section and arranged sothat one of its edges is disposed at right angles to the plane of thecaliper arms. As illustrated in Fig. 1 it will be seen that the blade 13is positioned with relation to the caliper arms so that the same are ina plane with the transverse center of said blade. A pair of links 14 arepivoted as at 15 to the arm 10 while the opposite ends of said links arepivoted to the caliper arms 5 as at 16. It will thus be seen that thearm 10 will be held centered between the points 6 at all timesregardless of the position of the arms.

It will be apparent from the foregoing that in use the calipers areadjusted to fit the end of a shaft or other cylindrical object in theordinary mannerand the device is then placed in the position illustratedin Figs. 1 and 2 whereupon a slight tap is given to the upper flat sideof the blade 13 thus making a mark on the end of the shaft. The calipersare then turned to a position at an angle to their original position andthe blade 13 is again struck and it will be apparent that a cross willbe formed in the end of the shaft and the inner section of the crosslines will indicate the center.

While in the foregoing there has been shown and described the preferredembodimentof this imention, it is to be understood that such changes maybe made in the combination and arrangement of parts as will fall withinthe spirit and scope of the appended claim.

What is claimed is The combination with a pair of calipers comprising apair of caliper arms pivoted together at one end, the opposite ends ofsaid caliper arms being pointed, means to adjust the pointed ends of thecaliper arms to various distances between the same, a blade carrying armslidably attached to the pivot edge disposed axially of the bladecarrying of the caliper arms and extending in a plane arm. 10 arrangedcentrally between the pointed ends In testimony whereof I aifix mysignature of the caliper arms, links pivoted to the calin presence oftwo witnesses.

iper arms and to the'blade carrying arm in- JAMES E. MURRAY. termediatetheir ends for holding the blade Witnesses:

carrying arm-centered and 'a blade at the JOHN P. MULLANE,

end of the blade carrying arm having its W. A. CUNNINGHAM.

